Evobrutinib, a covalent Bruton's tyrosine kinase inhibitor: Mass balance, elimination route, and metabolism in healthy participants

The highly selective, covalent Bruton's tyrosine kinase inhibitor evobrutinib is under investigation for treatment of patients with multiple sclerosis (MS). Early clinical studies in healthy participants and patients with relapsing MS indicated that evobrutinib is well-tolerated and effective. We undertook a mass balance study in six men who received a single 75-mg oral dose of evobrutinib containing ~ 3.6 MBq (100 μCi) 14 C-evobrutinib, to determine the absorption, metabolic pathways, and routes of excretion of evobrutinib. The primary objectives of this phase I study (NCT03725072) were to (1) determine the rates and routes of total radioactivity excretion, including the mass balance of total drug-related radioactivity in urine and feces, (2) assess the pharmacokinetics (PKs) of total radioactivity in blood and plasma, and (3) characterize the plasma PKs of evobrutinib. Exploratory end points included identifying and quantifying evobrutinib and its metabolites in plasma and excreta (urine and feces) and exploring key biotransformation pathways and clearance mechanisms. Evobrutinib was primarily eliminated in feces (arithmetic mean percentage, SD, 71.0, 2.1) and, to a lesser extent, in urine (20.6, 2.0), with most of the total radioactivity (85.3%) excreted in the first 72 h after administration. No unchanged evobrutinib was detected in excreta. Evobrutinib was rapidly absorbed and substantially metabolized upon absorption. Only one major metabolite M463-2 (MSC2430422) was identified in plasma above the 10% of total drug exposure threshold, which classifies M463-2 (MSC2430422) as a major metabolite according to the US Food and Drug Administration (FDA; metabolites in safety testing [MIST]) and the European Medicines Agency (EMA; International Conference on Harmonization [ICH] M3). These results support further development of evobrutinib and may help inform subsequent investigations.

Evaluation of the Relative Intranasal Abuse Potential of a Hydrocodone Extended-Release Tablet Formulated with Abuse-Deterrence Technology in Nondependent, Recreational Opioid Users

Objective

To assess the intranasal abuse potential of hydrocodone extended-release (ER) tablets developed with CIMA Abuse-Deterrence Technology compared with hydrocodone powder and hydrocodone bitartrate ER capsules (Zohydro ER, original formulation [HYD-OF]).

Design

Single-dose, randomized, double-blind, quadruple-dummy, active- and placebo-controlled, crossover study.

Setting

One US site.

Subjects

Healthy, adult, nondependent, recreational opioid users.

Methods

Subjects able to tolerate intranasal hydrocodone and discriminate hydrocodone from placebo were eligible for study enrollment. Eligible participants randomly received intranasal hydrocodone ER, intranasal hydrocodone powder, intranasal HYD-OF, intact oral hydrocodone ER, and placebo. Coprimary pharmacodynamic end points were a maximum effect on “at the moment” Drug Liking visual analog scale and Overall Drug Liking visual analog scale. Pharmacokinetics and safety were assessed.

Results

Mean maximum effect for “at the moment” Drug Liking was significantly (P < 0.01) lower for intranasal hydrocodone ER (72.8) compared with hydrocodone powder (80.2) and HYD-OF (83.2). Similar results were observed for Overall Drug Liking maximum effect (68.5 vs 77.1 and 79.8, respectively; P < 0.01). Secondary end points, including balance of effects and positive, sedative, and other effects, were consistent with these results. Intranasal treatments showed significantly greater effects vs placebo, while intact oral hydrocodone ER was similar to placebo. For each treatment, plasma concentration-time profiles paralleled “at the moment” Drug Liking over time. Incidences of adverse events for intranasal treatments were 52% for hydrocodone ER, 53% for hydrocodone powder, and 61% for HYD-OF.

Conclusions

The statistically significant differences between hydrocodone ER vs hydrocodone powder and HYD-OF for the primary drug liking end points indicate a lower intranasal abuse potential with hydrocodone ER in healthy, nondependent, recreational opioid users.

Abuse Potential with Oral Route of Administration of a Hydrocodone Extended-Release Tablet Formulated with Abuse-Deterrence Technology in Nondependent, Recreational Opioid Users

Objective. To compare the oral abuse potential of hydrocodone extended-release (ER) tablet developed with CIMA^® Abuse-Deterrence Technology with that of hydrocodone immediate release (IR).

Design. Randomized, double-blind, placebo-controlled, crossover study.

Setting and Patients. One study site in the United States; adult nondependent, recreational opioid users.

Methods. After confirming their ability to tolerate and discriminate hydrocodone IR 45 mg from placebo, eligible participants were randomized to receive each of the following oral treatments once: finely crushed placebo, hydrocodone IR 45-mg powder, intact hydrocodone ER 45-mg tablet, and finely crushed hydrocodone ER 45-mg tablet. Primary pharmacodynamic measure was “at the moment” drug liking. Secondary measures included overall drug liking, drug effects (e.g., balance, positive, negative, sedative), pupillometry, pharmacokinetics, and safety.

Results. Mean maximum effect (E_max) for “at the moment” drug liking was significantly lower for intact (53.9) and finely crushed hydrocodone ER (66.9) vs. hydrocodone IR (85.2; P < 0.001). Drug liking for intact hydrocodone ER was comparable to placebo (E_max: 53.9 vs. 53.2). Secondary measures were consistent with these results, indicating that positive, negative, and sedative drug effects were diminished with intact and crushed hydrocodone ER tablet vs. hydrocodone IR. The 72-hour plasma concentration-time profile for each treatment mimicked its respective “at the moment” drug-liking-over-time profile. Incidence of adverse events was lower with intact hydrocodone ER (53%) vs. hydrocodone IR (79%) and finely crushed hydrocodone ER (73%).

Conclusions. The oral abuse potential of hydrocodone ER (intact and finely crushed) was significantly lower than hydrocodone IR in healthy, nondependent, recreational opioid users. Hydrocodone ER was generally well tolerated.

Assessment of Alcohol-Induced Dose Dumping with a Hydrocodone Bitartrate Extended-Release Tablet Formulated with CIMA(®) Abuse Deterrence Technology

BACKGROUND

Greater drug content requirements for extended-release (ER) opioids necessitate greater protection against dose dumping. Hydrocodone ER employs the CIMA(®) Abuse-Deterrence Technology platform, which provides resistance against rapid release of the active moiety when the tablet is manipulated or taken with alcohol.

OBJECTIVE

Assess effects of alcohol on hydrocodone ER pharmacokinetics.

STUDY DESIGN

Open-label, crossover (January 25-April 30, 2010).

SETTING

Single center.

PARTICIPANTS

Forty healthy adults.

INTERVENTION

Subjects received all four treatments in a randomized manner (separated by a minimum 5-day washout): hydrocodone ER 15 mg with 240 mL water and 240 mL orange juice containing 4, 20, and 40% alcohol in a fasted state. Naltrexone was administered to minimize opioid-related adverse events.

MAIN OUTCOME MEASURE

Effect of alcohol on pharmacokinetics of hydrocodone ER assessed by comparing systemic exposure [maximum plasma drug concentration (Cmax) and area under the plasma drug concentration-versus-time curve from time 0 to infinity (AUC0-∞)] after administration with alcohol or with water.

RESULTS

Geometric means ratios of hydrocodone ER with 4, 20, and 40% alcohol relative to water were 1.05, 1.09, and 1.14, respectively, for Cmax and 1.07, 1.13, and 1.17, respectively, for AUC0-∞. All 90% confidence intervals for these geometric means ratios fell within the limits of 0.8 and 1.25. Increasing alcohol concentrations did not notably affect systemic exposure but were associated with increased adverse events.

CONCLUSIONS

Hydrocodone ER tablets were resistant to dose dumping when administered with alcohol in healthy subjects based on similar systemic exposures observed across all treatments.

Effects of Renal Impairment and Hepatic Impairment on the Pharmacokinetics of Hydrocodone After Administration of a Hydrocodone Extended-Release Tablet Formulated With Abuse-Deterrence Technology

Two open-label, single-dose, parallel-group studies assessed effects of renal and hepatic impairment on the pharmacokinetics of a hydrocodone extended-release (ER) formulation developed with the CIMA Abuse-Deterrence Technology platform. Forty-eight subjects with normal renal function or varying degrees of renal impairment received hydrocodone ER 45 mg (study 1); 16 subjects with normal hepatic function or moderate hepatic impairment received hydrocodone ER 15 mg (study 2). Blood samples were obtained predose and through 144 hours postdose. Mean maximum observed plasma hydrocodone concentration (Cmax ) in subjects with normal renal function, mild, moderate, and severe impairment, and end-stage renal disease was 28.6, 33.4, 42.4, 36.5, and 31.6 ng/mL, and mean area under the plasma hydrocodone concentration-versus-time curve from time 0 to infinity (AUC0-∞ ) was 565, 660, 973, 983, and 638 ng·h/mL, respectively. Incidence of adverse events was 57%, 38%, 44%, 33%, and 56%, respectively. Mean Cmax with normal hepatic function and moderate impairment was 10.1 and 13.0 ng/mL, and mean AUC0-∞ was 155 and 269 ng·h/mL, respectively. Incidence of adverse events was 38% in both groups. Altered systemic exposure in renally or hepatically impaired populations (up to ∼70% higher) should be considered when titrating to an effective dose of hydrocodone ER.

Effects of chlorophyll and chlorophyllin on low-dose aflatoxin B(1) pharmacokinetics in human volunteers

Chlorophyll (Chla) and chlorophyllin (CHL) were shown previously to reduce carcinogen bioavailability, biomarker damage, and tumorigenicity in trout and rats. These findings were partially extended to humans, where CHL reduced excretion of aflatoxin B(1) (AFB(1))-DNA repair products in Chinese unavoidably exposed to dietary AFB(1). However, neither AFB(1) pharmacokinetics nor Chla effects were examined. We conducted an unblinded crossover study to establish AFB(1) pharmacokinetic parameters among four human volunteers, and to explore possible effects of CHL or Chla cotreatment in three of those volunteers. For protocol 1, fasted subjects received an Institutional Review Board-approved dose of 14C-AFB(1) (30 ng, 5 nCi) by capsule with 100 mL water, followed by normal eating and drinking after 2 hours. Blood and cumulative urine samples were collected over 72 hours, and 14C- AFB(1) equivalents were determined by accelerator mass spectrometry. Protocols 2 and 3 were similar except capsules also contained 150 mg of purified Chla or CHL, respectively. Protocols were repeated thrice for each volunteer. The study revealed rapid human AFB(1) uptake (plasma k(a), 5.05 + or - 1.10 h(-1); T(max), 1.0 hour) and urinary elimination (95% complete by 24 hours) kinetics. Chla and CHL treatment each significantly impeded AFB(1) absorption and reduced Cmax and AUCs (plasma and urine) in one or more subjects. These initial results provide AFB(1) pharmacokinetic parameters previously unavailable for humans, and suggest that Chla or CHL co-consumption may limit the bioavailability of ingested aflatoxin in humans, as they do in animal models.

Absolute and relative bioavailability of fentanyl buccal tablet and oral transmucosal fentanyl citrate

This study assessed the absolute and relative bioavailabilities and transmucosal and gastrointestinal absorbency of fentanyl buccal tablet (FBT) and oral transmucosal fentanyl citrate (OTFC). In a randomized crossover design, 26 healthy subjects received FBT 400 microg (transmucosal), FBT 800 microg (oral), OTFC 800 microg (transmucosal), and fentanyl 400 microg (intravenous). The transmucosal FBT had the highest absolute bioavailability (0.65) compared with the oral FBT (0.31) or transmucosal OTFC (0.47). More fentanyl was absorbed transmucosally from FBT than OTFC (48% vs 22%). Median t(max) values were shorter following the transmucosal FBT (47 minutes) than the oral FBT (90 minutes) or the transmucosal OTFC (91 minutes). Transmucosal administration of FBT compared with dose-normalized OTFC resulted in higher total systemic fentanyl exposure, higher early systemic exposure, and higher C(max). The rate and extent of fentanyl absorption were greater following administration of FBT compared to OTFC. An approximately 30% smaller dose of FBT achieved systemic exposures comparable to OTFC.

Absorption of Fentanyl from Fentanyl Buccal Tablet in Cancer Patients With or Without Oral Mucositis

BACKGROUND AND OBJECTIVES

Patients with cancer, particularly those undergoing chemotherapy or radiotherapy, may develop oral mucositis. This is the first study to investigate the absorption profile of fentanyl buccal tablet (FBT) - an effervescent formulation of fentanyl indicated for the management of breakthrough pain in opioid-tolerant cancer patients - in patients with or without oral mucositis.

METHODS

In this open-label study, patients with or without oral mucositis self-administered a single 200 microg dose of FBT by placing the tablet between the upper gum and cheek above a molar tooth. Venous blood samples for measurement of plasma fentanyl concentrations were collected at regular intervals up to 8 hours following FBT administration. Parameters of interest included maximum plasma concentration (C(max)), time to reach C(max) (t(max)), area under the plasma concentration-time curve from time zero to 8 hours (AUC(8)), and AUC from time zero to the median t(max) (AUC(tmax)(')). Adverse events were monitored throughout the study. Oral mucosal examinations and measurements of vital signs were performed at intervals up to 8 hours following FBT administration.

RESULTS

Sixteen patients, 8 with and 8 without oral mucositis, received FBT and completed the study. The severity of oral mucositis was mild in the patients exhibiting this condition. Median C(max) values were comparable: 1.14 ng/mL (range 0.26-2.69 ng/mL) in patients with mucositis, and 1.21 ng/mL (range 0.21-2.34 ng/mL) in patients without mucositis. The t(max) was not significantly different in the two groups: median t(max) was 25.0 min (range 15-45 min) in patients with mucositis and 22.5 min (range 10-121 min) in patients without mucositis. Median AUC(tmax') values were 0.17 ng . h/mL (range 0.04-0.52 ng . h/mL) in patients with mucositis, and 0.20 ng . h/mL (range 0.00-0.65 ng . h/mL) in patients without mucositis. The corresponding AUC(8) values were 2.05 ng . h/mL (range 1.16-3.83 ng . h/mL) and 1.55 ng . h/mL (range 0.74-3.07 ng . h/mL), respectively. FBT was generally well tolerated in this small group. No application site adverse events or changes in oral mucosal assessments were reported.

CONCLUSION

The absorption profile of a single dose of FBT 200 microg was similar in patients with or without mild oral mucositis. The compound was generally well tolerated.

Pharmacokinetic properties of fentanyl effervescent buccal tablets: A phase I, open-label, crossover study of single-dose 100, 200, 400, and 800 μg in healthy adult volunteers

BACKGROUND

The fentanyl effervescent buccal tablet (FEBT) is designed to enhance the rate and extent of the absorption of fentanyl, an opioid, through the buccal mucosa.

OBJECTIVES

The purposes of this study were to assess the dose proportionality of FEBT in healthy volunteers over the potential therapeutic dose range (100-800 microg) and characterize the pharmacokinetic (PK) profile of 4 doses (100, 200, 400, and 800 microg) of FEBT.

METHODS

This Phase I, randomized, open-label, 4-period crossover study was conducted at Radiant Research, Honolulu, Hawaii. Healthy adult volunteers with intolerance to opioids were randomly assigned to receive 1 of 4 single-dose sequences of FEBT: 100, 200, 400, and 800 microg (selected to encompass the anticipated therapeutic dose range), with each successive administration separated by a washout period of >or=7 days. Naltrexone hydrochloride (50-mg tablet) was administered-15 and 3 hours before and 9 hours after FEBT administration to block opioid receptor-mediated effects of fentanyl. Plasma fentanyl concentrations were measured from venous samples obtained over 72 hours after FEBT administration. Early fentanyl exposure was assessed using AUC from time 0 to 0.75 hour (the median T(max) of the reference dose [100 microg]) (AUC(0-Tmax')). Adverse events (AEs) were monitored and recorded throughout the study by medically qualified personnel.

RESULTS

Thirty-two subjects (26 men, 6 women; mean [SD] age, 29.3 [7.2] years [range, 19-44 years]; mean [SD] weight, 74.7 [10.7] kg) were enrolled. Median T was between 35 and 45 minutes after FEBT administration. AUC(0-infinity) and C(max) increased approximately linearly with increasing doses of FEBT. Mean plasma fentanyl concentrations decreased from C(max) in a biexponential manner at the 100- and 200-microg doses and decreased in a triexponential manner at the 800-mug dose. Despite the triexponential decrease in the mean profile observed with the 400-microg dose, a biexponential decrease was observed in approximately half of the individual profiles. AUC(0-Tmax') ranged from 0.09 ng x h/mL with the 100-microg dose to 0.52 ng x h/mL with the 800-microg dose. The most commonly reported AEs in the 100-, 200-, 400-, and 800-microg dose groups were as follows: application-site erythema, 3, 3, 4, and 3 subjects, respectively; nausea, 3, 2, 5, and 4 subjects; somnolence, 3, 2, 3, and 2 subjects; and headache, 3, 2, 1, and 4 subjects. None of the AEs were serious.

CONCLUSIONS

In this study of the dose proportionality of FEBT in healthy volunteers, the PK profile of FEBT was characterized by a high early systemic exposure of fentanyl (0.09-0.52 ng x h/mL). Dose-dependent parameters (C(max) and AUC) increased in an approximately dose-proportional manner from 100 to 800 microg FEBT.

In vivo modulation of the rat cytochrome P450 1A1 by double-stranded phosphorothioate oligodeoxynucleotides

CYP1A1 gene expression is regulated by known cis- and transacting elements controlling inhibition and induction of CYP1A1 transcription. The influence of a double-stranded phosphorothioate oligonucleotide (dsODN) with sequence identical to the CYP1A1 negative regulatory element (NRE) was examined in Sprague-Dawley rats. Two strategies were employed: (i) two single-stranded complementary 25-mer ODNs that form a double-stranded ODN (ODN1) and (ii) a 54-base, self-complementary ODN which forms a dsODN hairpin (ODN2). A dsODN hairpin with scrambled NRE sequence was evaluated as a control (ODN3). Zoxazolamine paralysis times, an in vivo marker of CYP1A1 activity, were reduced from 184 +/- 18 min in saline-treated rats to 103 +/- 12.5 min 24 hr after a single 1.7-mg ODN1 iv injection. Liver microsomal EROD, an in vitro marker of CYP1A1/2 activity, was increased from 210 +/- 10 pmol in saline-treated animals to 703 +/- 73 and 623 +/- 89 pmol resorufin/mg protein/min after iv ODN1 and iv ODN2, respectively. ODN1's activity did not change PNP hydroxylation and PROD, markers of CYPs 2E1 and 2B1/2. ODN2 did not significantly change PNP but did significantly alter PROD. The ODN3 did not cause any significant changes in any assay measured. The ODN1-induced responses in ZX paralysis and EROD were observed post-iv injection, but not following ip injection of ODN1. Western blot analysis of ODN1- and HPO-treated rat liver microsomes also revealed increased in CYP1A1 protein. These data indicate double-stranded ODNs mimic the cis-acting NRE in vivo inducing CYP1A1 in the absence of other xenobiotics.